Ethyl (hydrocarbyloxyethyl) carbamates



United States Patent O 3,326,962 ETHYLROCARBYLOXYETHYL) CARBAMATESGeorge E. Ham and Leonard Levine, Lake Jackson, Tern, assignors to TheDow Chemical Company, Midland,

Mich, a corporation of Delaware No Drawing. Filed Nov. 20, 1963, Ser.No. 325,159 9 Claims. (Cl. 260-471) This invention relates to carbamatecompositions and to methods of praparing such compositions. Moreparticularly, this invention relates to carbamates which contain analkoxyalkyl group attached to the nitrogen atom of the carbamate and tothe preparation of such carbamates by the reaction of an alkyl1-aziridinylcarboxylate (including esters in which the aziridinyl groupcontains substituents in the 2 and 3 positions) and an alcohol in thepresence of an acidic material.

It is known that thiophenol reacts with alkyl l-aziridinylcarboxylatesto produce alkyl Z-phenylthiocarbamates without a catalyst, as disclosedby Iwakura' et al. in J. Org. Chem., 26, 4384-8 (1961). However, phenolsdid not react similarly in non-catalytic systems either at room orelevated temperatures.

It has now been found that alcohols will react with alkyl esters ofsubstituted and unsubstituted l-aziridinylcarboxylic acids in thepresence of an acidic catalyst to produce the corresponding carbamatecompound.

The reaction may be represented by the following wherein each R isindependently selected from the group consisting of the hydrogen atomand a lower alkyl group of from 1 to 4 carbon atoms and each R may be ahydrogen atom, an alkyl group of from 1 to 11 carbon atoms or an arylgroup of from 6 to 10 carbon atoms (such as phenyl, tolyl, cumyl,phenylethyl, naphthyl or duryl) and R is a lower alkyl group of from 1to 4 carbon atoms. Thus, each R and R may be a methyl, ethyl, n-propyl,i-propyl, n-butyl, sec.-butyl, tert.-buty1 or i-butyl group and each Rmay be any of these groups plus a pentyl, hexyl, heptyl, octyl, nonyl,decyl or undecyl group.

As starting materials, alcohols such as methanol, ethanol, 2-propanol,n-butanol, t-butyl alcohol, isobutyl alcohol, l-pentanol, hexanols,heptanols, octanols, decanols, undecanols, dodecanols (such as laurylalcohol), benzyl alcohol, stearyl alcohol and 3-phenyl-1-propanol may beused. Suitable reactants include alcohols of up to 20 or 30 carbonatoms, such as alkanols of from 1 to '18 carbon atoms. Each of thesealcohols may be reacted with alkyl 1-aziridinylcarboxylates such asmethyl 2 methyl 1- aziridinylcarboxylate, ethyl 2,3diethyl-l-azirdinylcarboxylate, ethyl Z-n-butyl-l-aziridinylcarboxylate,n-propyl l-aziridinylcarboxylate, ethyl2-n-propyl-l-aziridinylcarboxylate and t-butyl l-aziridinylcarboxylateto produce the corresponding carbamate compound.

The acidic catalyst used in the process may be any Lewis acid (electronacceptor) which behaves as a proton, such as BF SnCl BCl ZnCl AlCl etc.,or a conventional acid material which produces a proton (or a solvatedproton) such as H 80 HCl, HBr, HNO etc. Only a catalytic amount ofacidic material is required.

Patented June 20, 1967 "ice Generally from about 0.001 mole to .10 moleof acidic catalyst per mole of alkyl l-aziridinylcarboxylate issufficient. Non-volatile acidic materials are preferably employed ascatalysts in the process.

The reaction may be carried out at temperatures of from about C. to 200C. (usually at from ---80 C. to C. and preferably at room temperature)using pressures of from .5 atmosphere to 2 or 3 atmospheres orautogenous pressures developed during the reaction. The amount ofalcohol used in the reaction should be at least one mole of alcohol permole of carboxylate group. If less than about 0.5 mole of alcohol permole of carboxylate group is used, a smaller amount of carbamate isproduced, since the limiting reactant is the alcohol when less than anequimolar ratio is used. Mole ratios of alcohol to carboxylate group offrom 1:1 to 50:1 may be used, and ratios of from 2:1 to 20:1 arepreferable. The process operates effectively when from 2 to 20 moles ofalcohol per mole of carboxylate group are reacted in the presence of anamount of catalyst sufficient to provide from .005 to .01 mole ofnon-volatile acidic catalyst per mole of carboxylate group at roomtemperature under atmospheric or autogenous pressure.

The compounds of the invention are useful as bactericides in eitherconcentrated or dilute solutions or dispersions. The compounds areespecially effective for inhibiting or preventing the growth of E. coli.In addition, the compounds may be used as inhibitors and stabilizers forhaloalkanes which deteriorate in the presence of aluminum metal. Thecompounds are good inhibitors when incorporated into such haloalkanes(for example, methyl chloroform) in amounts suflicient to give aconcentration of up to about 15 percent (based on the total weight ofthe composition). Only an inhibiting amount of the compound is necessaryand concentrations of from about 0.5 to 5 percent are ordinarilysuflicient for methyl chloroform stabilization.

The following examples are submitted for the purpose of illustrationonly and are not to be construed as limiting the scope of the inventionin any Way.

Example 1.-General procedure Tto a stirred, refluxing solution (118 C.)of 60 grams (0.81 mole) of n-butanol and 0.45 gram of boron trifiuorideetherate was added dropwise a solution of 17.6 grams (0.153 mole) ofethyl l-aziridinylformate (ethyl l-aziridinylcarboxylate) and 21 grams(0.28 mole) of n-butanol. The solution was diluted with diethyl ether,washed with saturated NaCl solution and finally dried over anhydrouscalcium sulfate. The reaction mixture was filtered and the filtrateconcentrated at reduced pressure. Vacuum distillation of thisconcentrate yielded 19.4 grams (67 percent of theory) ofethyl(2-butoxyethyl)- carbamate which distilled at 56 59 C. at 0.1 mm.pressure, 1 =1.4339.

The infrared spectrum was consistent with the formula:

Hydrolysis of a sample of this product gave 2-butoxyethylamine[identified by preparation of the solid picrolonate (melting point 172C.) by reaction with picrolonic acid].

Examples II-IX In a similar manner, other alcohols were reacted usingacidic catalysts. The results and compounds prepared are summarized inTable 1.

TABLE 1 Reactants and Proportions Example Reaction Temp. Catalyst(grams, Yield Boiling Point/ Number C.) unless noted) Product (percentof mm. Hg

Alcohol Moles Moles theory) Alcohol EAF* II Methanol. 1.91 0.20 25Ocgngc. (98 percent) H2804, (A) 81 65-66/1.0 1.4354

. 0C. Ethanol... 0.00 0.20 Lorain-(0113011920 (B) 61.8 92 .5 1.4335l-butanol. 0.844 0.20 25 Gone. (98 percent) 11250.1, (0) 00 8590/0.11.4384

do. 0.80 0.153 8990.(3.5 hours) 0.35 BF3-(CH3CH2)20.-. (D)- 49 do 0.300.153 118-121 (2.5 hours) 04513153 (CH3CII2)zO e7 2-butanol- 0.80 0.15397-101(4hours) 0.45 BF3 (0113011920-. 55 6162/0.3 1.4310

1-deeanol 0.72 0.153 117-120 (3 hours) 0.45 BF3-(CHaOH2)zO- 7510s-110/0.1 1. 4439 BenzyL.-- 0.80 0.153 118-121(3 hours) 0.45BFg-(CHgOHfizO 50 -100/0.1 1.5053

*EAF=Ethyl l-atiridinylformate (ethyl l-aziridinyloarboxylate).

i t (I) 1'1 (E) CHaCHzOCN-CH2CHO(CHMOH; (A) CHaCHzO-C-N-CHzOHzOCHs (H) Ii (EH3 o Ell (F) CH5CH1OCN-CHzCH2O(%CH2CHa (B) CHaGHzO-CNCH2GH2OCHzCHs Hi i u i (G) CH3OHzO-CNCH2CH30(CH2)3CH3 (G) CH3CHzOCNCH2CH O{CHz) OH t ei t r I (D) CHaCHzO-C-N-CHzCHzO(CH2)3CH3 (H) CHSCHZO" C NCHZOHZO CIQExample X 5 with an ester of the formula The carbamates prepared in theabove examples were H tested as bactericides by streaking the compoundsin a 0 (|3 R nutrient agar which was cross-streaked with E. coli. E.coli did not grow at the place where a streak of the bac- 1OCN\ terialsuspension crossed the streak of test compound. When the compounds ofExamples IV, VII and VIII I were incorporated at 4 percent (weight)concentration in methyl chloroform, good inhibition of the methyl.whfirein; chloroform against attack by aluminum metal was ob- (a) eachR0 is independfinfly selected from the group talnedconsisting of ahydrogen atom and a lower alkyl We clalm as our mventlon: group of from1 to 4 carbon atoms, A compound of the formula (b) R is a lower alkylgroup of from 1 to 4 carbon atoms and o H R H H u l (c) each R isselected from the group consisting of the E- hydrogen atom, an arylgroup of from 6 to 10 car- R0 R0 '11 bon atoms and an alkyl group offrom 1 to 11 carwherein. bon atoms in the presence of an acidic catalystse- (a) each R is independently selected from the group 2 6 53 1 1 2;groupflloponsrstmg of a Lewis ac1d,

consisting of a hydrogen atom and a lower alkyl r 3 group of from 1 to 4carbon atoms,

(b) R is a lower alkyl group of from 1 to 4 carbon atoms, and

(c) Ris an aryl group of from 6 to 10 carbon atoms.

2. The compound:

3. A process for preparing carbamates which comprises reacting analcohol of the formula 4. The process of claim 3 wherein the ester andalcohol are reacted at temperatures of from C. to C.

5. The process of claim 4 wherein the acidic catalyst is a Lewis acid.

6. A process for the preparation of a carbamate which comprises reactingan alkanol of from 1 to 18 carbon atoms with an ester of the formulawherein R is a lower alkyl group of from 1 to 4 carbon atoms, in thepresence of an acidic catalyst selected from the group consisting of aLewis acid, H 50 HCI, HBr and HNO 3,826,962 5 6 7. The process of claim6 wherein the reaction is carpresence of a member selected from thegroup consisting ried out at temperatures of from -80 C. to 100 C. of BFand H 80 and wherein the acidic catalyst is a Lewis acid.

8. The process of claim 6 wherein the reaction is car- References Citedried out at temperatures of from 80 C. to 100 C. and 5 Iwakura et aL JOrg chem 26 4384 8 (1961) wherein the acidic catalyst is selected fromthe group con- Lucas Chem 3531};

sisting of H 50 HCl, HBr, and HNO A Rmcess fr.PreParing P LORRAINE A.WEINBERGER, Primary Examiner. mate which comprises reactingStOlCl'llO'Il'lCtIlC amounts I of n-butanol and ethyll-aziridinylcarboxylate in the 10 DANIEL D-HORW1TZ,ExamlIl6F-

1. A COMPOUND OF THE FORMULA